Firearms such as rifles normally include a relatively elongated barrel that is gripped by a user during firearm operation. Because the barrel may become hot with repeated firing, the firearm is normally equipped with a hand guard that is positioned about an exterior surface of the barrel. During operation, the user may grip the hand guard to protect his hand from heat radiating from the barrel as rounds of ammunition are discharged.
Typically, the hand guard is secured to the firearm between a front sight base, which is used to sight the firearm, and a barrel nut, which is used to attach the barrel to the firearm. The hand guard is positioned between the front sight base and the barrel nut such that a forward end of the hand guard is inserted into a hand guard cap adjacent to the front sight base, and a rearward end is positioned about the barrel nut. A spring-loaded delta ring then extends over the rearward end to capture the hand guard against the barrel nut, securing it to the firearm. Because the hand guard is connected to the firearm at both its forward and rearward ends, the attachment may be relatively secure. Such a configuration is described in U.S. Pat. No. 3,090,150 entitled “Hand Guard Construction.”
To accommodate one or more accessories, the hand guard may have a rail system. The rail system extends about an exterior of the hand guard and provides a mounting surface for attaching accessories. The upper receiver may also have rail system, but because the upper receiver is separated from the hand guard by the delta ring and barrel nut, the disparate rail systems of the upper receiver and the hand guard usually do not connect with each other. That is, the disparate rail systems do not provide a continuous mounting platform between the upper receiver and the hand guard because the mounting surfaces provided by the rail systems are interrupted. While a rail extension member can be used to connect the two rail systems, the rail extension member must be sized to extend over the barrel nut and delta ring, which alters the line of the sight for the user and results in incompatibility with certain accessories.
One problem with conventional hand guards is that such hand guards are not free-floating. A free-floating hand guard is attached to the firearm at a single point but is otherwise spaced apart from the barrel in a radial direction. The space forms an air gap about the barrel that dissipates heat. The space also provides a relief area for absorbing displacement caused by the grip of the user or the weight of an accessory, which otherwise may affect the direction of the projectile and the accuracy of the firearm. Thus, replacing a conventional hand guard with a free-floating hand guard may be generally desired. At the same time, because the free-floating hand guard is attached at only one point, the connection between the hand guard and the firearm is relatively less secure. Consequently, a free floating hand guard may not have a relatively secure connection to the firearm to permit attaching heavy accessories or withstanding expected vibration and jostling. For example, the hand guard may tend to wobble.
While some free-floating hand guards may attach more securely, such hand guards rely on a bulky attachment structure that clamps the hand guard about an outer circumferential surface of the barrel nut. These bulky attachment structures, though, may increase the height or disrupt the profile of the firearm, impeding the line of sight of the user and/or the use of a rail system.